Mechanical time fuse



March 25, 1930. P. LIEBERGELD 1,752,188

y MECHANICAL TIME FUSE Filed 0G13, 25, 1928 2 Sheets-Sheet l ,i l 1 1 1 1 l l 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1.

/NYeA/Tdf March 25, 1930.

P. LIEBERGELD MECHANICAL TIME FUSE Filed Oct. 25, 1928 2 Sheets-Sheet 2 hx" @M i Patented Mar. 25, 1936 UNITE PAUL LIEBERGELD, OF BAD THAL, GERMANY MECHANICAL TIME FUSE Application filed October 25, 1928, Serial No This invention relates to mechanical time fuses with clockwork mechanism and has for its object to prevent so-called premature eX- plosions with time fuses of this kind.

The invention relates more particularly to time fuses of the kind in which the clockwork shaft carries a pointer which, at the moment of firing, is liberated by a securing device which has secured it up to that moment in the inoperative position and thereupon coacts with an adjustable time determining ring, finally passing through a gap in the said time determining ring and at the same time liberating the ignition device previously secured by it.

In time fuses of this kind it may occur, that the time determining ring is inadvertently wrongly adjusted and that, when the gun is iired, the gap in the ring will occupy its zero position with respect to the pointer of the vclockwork mechanism, so that at the moment of firing the pointer can immediately pass through the said gap, thus initiating the ignition. The projectile will in that case explode shortly after it has left the barrel and will inevitably cause considerable damage. The present invention has for its object to overcome this difficulty in a reliable manner.

The invention consists more particularly in this, that besides the securing device for the pointer, which is released at the moment of liring, a second securing device is provided between the pointer and the time determining ring, whichat first remains edective even after the gun has been fired and prevents only the coaction of the pointer with the time determining ring, but not the rotation of the pointer, for a period of time, which suiiices for preventing a premature explosion within a predetermined distance.

The accompanying drawings illustrate two constructional examples of the invention,

Fig. l being a side elevation of the upper portion of one constructional form of the clockwork to be enclosed in the fuse,

Fig. 2 the corresponding plan view,

Fig. 3 a side elevation in part section of the upper portion of the second constructional form of the clockwork and 315,078, and in Sweden September 15, 1928.

Fig. l the corresponding plan view.

In the construct-ional form shown in Figs. l and 2 of the drawing 1 is the clockwork support and 2 the shaftof the clockwork, which puts the clockwork mechanism housed within the support in rotation. The upper part oi the shaft 2 of the clockwork mechanisni is provided with a guiding slot 3 in which the bridge-like transverse member 4 of a ring 5 is capable of sliding vertically. On the ring pointer 6 is fixed which a compression spring not shown in the drawing continuously seeks to force upward in a known manner, the bridge-like transverse member Llbeing of course forced to slide upward in the slot 3, without however the carrying round of the pointer by the rotating clockwork shaft 2 being interfered with. By a hook-shaped securing member 7 which is pivoted about the pin 8 in the clockwork support l so as to rotate in a vertical plane and engages with a bevelled projecting rib 9 over the upper edge of the pointer 6 in the opposite direction to the direction of rotation of the latter the pointer is prevented up to the moment of `tiring from yielding to the upwardly directed pressure of the spring referred to, that is to say it is retained in the inoperative position shown in Fig. l on the upper side of the casing l of the clockwork mechanism. At the moment of firing, however, the hook-shaped securing member 7 rops downwards owing to its inertia, so that its rib 9 can slide od the upper edge of the clockwork pointer G, which is to the right in Fig. 2, thus releasing the pointer. The latter is thus able to follow the pressure of the spring and to move upwards until it rests with its two ends against the horizontal time determining ring 10 positioned above the clockwork support l. As in the time uses of a known kind the pointer 6 thereupon slides along the said ring under the action of the running down clockwork, until it arrives at a gap 1l provided in the time determining ring l() and, still under the pressure of the said spring, can pass upwards through the said gap whereupon it releases the ignition device in a known manner and brings about the explosion of the projectile. The dura- ,j the pointer 6 damage due to tion of the flight'of the projectile depends upon the angle through whichV the pointer has to travel from the moment of its release by the hook-shaped securing member, till it passes throughthe gap 11, which angle. can be varied as desired by the previous adjustment of the time determining ring.

Infuses of this kind it may occur owing to hurry'or inadvertence that the time determining ring 10 is incorrect-ly set and may by chance be at Zero or thereabouts, so that at the moment of firing the gap 11 will lie above the'clockwork pointer 6.' Y ln this case the pointerwhich, as already stated, is released at the moment of firingby the securing device 7, 9, is free to pass directly through the gap 11 and thus to cause the ignition of the projectile, in other words, the projectile will in this case explode ust after leaving the barrel and thereby inevitably cause serious damage. The object of the invention is to provide absolute security against such an occurrence, andthis is effected in the following manner: i YOn the side lying opposite the securing member 7, second securing member 12 for the pointer 6 is provided, which however is fired and which consists of a block fixed by means of two screws 13 rigidly on the upper surface of the clockwork support 1 and having a horizontallug 14 engaging over the pointer when in the Zero position. lug the clockwork pointer 6 is for the time being held back in the position shown in Fig. 1, even after it has been released at the moment of firing by thev hook-shaped securing member 7. Consequently the pointer will'be prevented for a time after theV moment of firing. from yielding to the pressure of the spring and from sliding upwards on the shaft ofthe clockwork for coacting with'the timedetermining ring 10. rlhe rotary vInotionY of the clockwork shaft 2 which commences immediately after the release of the .Securing member '7 and consequently the rotary motion o f the pointer 6 is however in no .waylinterfered with by the lug 14 of the second securing member 12. VThe length of the lug 14 is made such that the pointer 6 can only slide off it and thereupon coact with the time determining ring 10, when a predetermined periodof time has elapsed and the projectile has thus travelled a certain distance.V Even should the gap 11 in the time determining ring 1() lie immediately above the fuse, the pointer 6 can only pass through the gap 11 and ignition can only take place `after this path has been travelled through, in other words, at a distance in which any longer to be feared.V

rlhe arrangement ac- Y cording` to the invention thus precludes with By this .slide off after the projectile has travelled for a certain Y through an incorrect setting of` Vthe pointer at the moment termining ring capable lo f'coacting with the said pointer, al gap in the time Y premature explosion is no Y opposite the gap,

In the constructional form shown in Figs. 3 and l the pointer 15 is not slidable 0n the shaft 16 of the vclockwork but is fixed rigidly thereon, so that it can only turn together with it. The forward part of the pointer is provided with a bar in which a pin 18 loaded by a compression spring-17 is. slidable, which pin, when in the inoperative position (Fig. 3), engages with its rear end over a spring-loaded cap 19 which secures the ignidirectedand the gap21 in the ring does not allow the passage of the pointer V15 itself but of the spring-loaded pin 18 of the pointer. As' soon as the pinhas Ventered the -gap 21 under the actionof the spring 17 the pin 18 releases the cap 19 and consequently the ignition device, thus initiating the ignition. ln order, however, that this can take place only after the projectile has travelled a vcertain .distance,.an angleV piece 22 isfiXed to the casing 1, against the upwardly 'directed part-23 of which the pin` 18 rests under theaction of the spring-V17, so that the pin cannot for the time-beingcoact with thetime determining ring 2O and pass through the gap'21 in the same, without however the rotary motion y ofthe pointer '15' being prevented' byy the angle 22, 23. 'lhe length of the part 23 is made such that the`sprin rloadedpin 18 can the saidpart 23 in any. case/only time and can rest against thetime det'ermin` ing ring 20, sliding along the latter till, after the desired periodof time, it passes through the gap 21 and initiates constructional formY of the invention as well a premature explosion is prevented with absolute A certainty within the radius of safety, even vwhemow'ing` to faulty setting of the time ydetermining ring,"the gap 21 in the latter should at the moment of firing be exactly opposite the pin 18 in the pointer.

4What I claim is: i

the ignition. In this Y 1i A.mechanicaltime fuse for projectiles, Y

comprising in combination a clockwork mech` anism, arotary shaft inthe said mechanism, a pointer mounted on the shaft, a first securingjdevice for securing the pointer in the inoperative position and capableY of releasing of firing, a time dedetermining ring, means for causingy the pointer to engage through the saidfgap on "the pointer coming I p an igniting'device Vcapable of being secured inthe inoperative position and of being released by the said pointer, a second securing device for the pointer positioned between the pointer and the time determining ring and capable of remaining effective after the moment of firing for preventing the coaction of the pointer and the time determining ring, but not the rotary motion of the pointer, for a period of time which is suhcient tor preventing a premature eXplosion of the projectile Within a predetermined radius of safety, as set forth.

2. A mechanical time fuse for projectiles,

Vcomprising Vin'combination a clockwork mechanism, a support for the said clockwork mechanism, a rotary shaft in the said mechanism, a pointer mounted on the shaft so as to be capable of sliding axially thereon, a lirst securing device for securing the pointer in the inoperative position and capable of releasing the pointer at the moment of firing, a time determining ring extending above the pointer and capable of coacting with the said pointer, a gap in the time determining ring, means for causing the pointer to engage through the said gap on the pointer coming opposite the gap, an igniting device capable of being secured in the inoperative position and of being` released by the said pointer, a second securing device for the pointer, comprising a cranked member liXed to the said support, one part of which cranked member projects over the pointer in the direction of rotation of the latter when in the zero position and is of such a length that the pointer can only become disengaged from it, when the projectile has passed beyond a predetermined radius of safety and thus become free to coact with the time determining ring, as set forth.

In testimony whereof I have signed my name to this specification.

PAUL LEBERGELD. 

